Merge pull request #142 from rezzza/fix_autoload

Alias on a real class must be done only if the autoloader has loaded the real class, thanks to @stephpy for its help.

classes/autoloader.php

@@ -110,7 +110,7 @@ public function requireClass($class)
 			require $path;
 		}
 
-		if ($realClass != $class)
+		if (class_exists($realClass, false) === true && $realClass != $class)
 		{
 			class_alias($realClass, $class);
 		}